ztest has unnecessary dependencies on its directory
The ztest utility (used to test the ZFS kernel module in userland, among other things) has an oddity which makes it difficult to use:
It assumes that, if running /usr/bin/amd64/ztest, that zdb must be present in /usr/sbin/amd64/zdb. Which makes sense, except that we (SmartOS) don't deliver ztest and zdb in our platform, rendering those tools useless unless they're delivered with the platform. In addition, ztest will dump core if it doesn't find zdb.